Second Opinion From an Oncologist: When You Need One and How to Get It

Not everyone needs a second opinion from an oncologist, but in some situations it really can change the decision: a rare tumour, unclear pathology, doctors who disagree, a difficult choice, or progression. The key is to get it quickly, with a complete set of documents and without breaking off with your treating doctor.

Below I explain when I advise patients to get a second opinion, what to expect from it and how to prepare so you lose neither time nor your relationship with the doctor who is treating you.

When a second opinion is really needed

If the diagnosis is typical, the stage is clear and the treatment plan matches clinical guidelines, a second opinion most often simply confirms the chosen approach. That has value too — peace of mind helps you get through treatment. But there are situations where I would definitely not skip this step.

• A rare tumour. The rarer the disease, the fewer doctors have seen it many times. The view of a specialist who works with that particular type can add a lot.
• Unclear or conflicting pathology. The report says “cannot be excluded” or “differential diagnosis with…”, the biopsy and surgical results don’t match, or there is no IHC (immunohistochemistry — staining that clarifies the type of tumour) or molecular testing that is usually needed for this diagnosis.
• Doctors say different things. The surgeon suggests one thing and the medical oncologist another, or two hospitals have proposed different plans.
• A difficult decision. Disfiguring surgery, a choice between several treatment options, or a decision whether to continue or stop drug treatment.
• Progression. The tumour is growing despite treatment, and the question is what comes next: another line of treatment, molecular testing, a clinical trial.

The American Cancer Society lists similar reasons: a rare or unusual cancer, uncertainty about the type or stage, and several treatment options on the table.

I’ll also be honest about something else: a 2016 systematic review found that, across different studies, a second opinion changed the diagnosis or recommendations at very different rates. So I don’t promise that a consultation will necessarily turn everything around. Its job is to check that the decision rests on an accurate diagnosis and complete information.

Why reviewing the pathology slides matters so much

All cancer treatment is built on the pathological diagnosis — on what the pathologist saw under the microscope in the slides and paraffin blocks (pieces of tissue embedded in paraffin, from which sections are cut). If there is an error or inaccuracy at this stage, the treatment plan can’t be right either.

Discrepancies on review are more common than people think. Here are the data from two large studies in which the slides of referred patients were reviewed by subspecialist pathologists:

These figures come from one large cancer centre and don’t transfer directly to every laboratory. But they show clearly that a slide review is not a formality — it’s a way to catch an error before treatment starts.

If the doubts concern the diagnosis itself, a second opinion without reviewing the slides and blocks is an opinion based on someone else’s description. Pathology first, then a discussion of the plan.

In practice it works like this: you collect the slides and blocks from the laboratory or archive (they are released against your signature, sometimes on written request) and send them to a reference laboratory. Check in advance exactly what it accepts and whether you need a referral. I explain how to read the report itself in my article “How to read a pathology report”, and the markers in breast cancer in my piece on IHC: ER, PR, HER2, Ki-67.

What you can and can’t expect from an online consultation

The online format is convenient when you live in another city or country and a decision needs to be made soon. But it has honest limits, and I always spell them out in advance.

What an online consultation can offer:

• a review of all your documents: pathology, IHC, CT, MRI and PET-CT reports, blood tests, discharge summaries;
• an assessment of how well the proposed plan matches clinical guidelines;
• an understanding of which tests or investigations are still missing for a decision;
• an explanation of the treatment options in plain language, without rushing;
• a list of questions worth asking your treating doctor.

What an online consultation does not do:

• it doesn’t make a diagnosis remotely;
• it doesn’t prescribe treatment or change doses;
• it doesn’t replace examination and follow-up by your treating doctor.

This isn’t overcaution on my part — it’s a legal requirement. Article 36.2 of Russian Federal Law No. 323-FZ sets out the purposes of telemedicine consultations: collecting and analysing symptoms and medical history, assessing how well treatment is working, monitoring, and deciding whether an in-person appointment is needed. Previously prescribed treatment can be adjusted remotely by the treating doctor — and only if the diagnosis was made and the treatment prescribed at an in-person appointment.

So my recommendations after a consultation are material to discuss with your treating doctor, not a prescription in their own right.

My online consultation takes place on Zoom and lasts about 60 minutes; afterwards you receive a written summary: what I saw in your documents, what the options are and what needs clarifying. If you’d like, I’ll go through your documents in a second-opinion consultation.

Which documents to gather

How useful a second opinion is depends on how complete your documents are. An incomplete set is the most common reason a consultation ends with “we need to look further”.

1. Discharge summaries from all hospitals and the conclusions of tumour boards (multidisciplinary team meetings).
2. Pathology reports — from the biopsy and from surgery, if you had it. Plus IHC and molecular tests.
3. Operation notes, if you had surgery.
4. CT, MRI and PET-CT reports, plus the discs with the scans themselves. A report is one radiologist’s opinion; the disc lets someone look at the images. More on the methods in my article “PET-CT, CT or MRI: what they’re for”.
5. Blood tests: full blood count and biochemistry, tumour markers if they were measured — ideally over time.
6. A list of all your medicines with doses, including those not for cancer: for blood pressure, diabetes, as well as supplements and herbs.
7. The current treatment plan, if one has been proposed: which regimen, how many cycles, what’s planned next.

Scan everything in good quality and arrange it by date. Keep the originals; give copies to the doctor.

How not to lose time

A second opinion shouldn’t turn into a long search. A few rules I usually suggest:

• Ask your treating doctor how long you can wait. There is usually a little time to think, but with some cancers the decision needs to be made straight away. The American Cancer Society also advises discussing the timing with your doctor first.
• Run things in parallel. While the slides are on their way for review, you can have the missing tests done and book the consultation.
• Don’t collect a third, fourth and fifth opinion. If two specialists disagree, it’s more useful to ask each to explain their reasoning: how they interpret the scans and which guidelines they rely on. That usually makes it clear what the disagreement is really about.
• Don’t put treatment that has already started on hold on your own. If therapy is under way, the decision to pause it is made by your treating doctor.

How not to offend your treating doctor

Many patients are afraid of damaging their relationship with the doctor who is treating them. In oncology a second opinion is normal practice, and most colleagues take it calmly. Being direct helps.

You could say something like: “This is a very serious decision for me, and I’d like to hear from one more specialist. Could you prepare copies of my documents?” You can even ask your doctor whom they would refer you to themselves.

After the second opinion, go back to your treating doctor with specifics: “It was suggested that we discuss this test” or “I have a question about the stage”. That way you stay on the same team, and the decision is made on the basis of complete information.

Questions to ask your oncologist

• How urgently does treatment need to start, and is there time for a second opinion?
• Do I need a review of the slides and blocks, and where is the best place to send them?
• Have all the necessary tests been done — IHC, molecular testing?
• What other treatment options did you consider, and why did you choose this one?
• What exactly is the diagnosis and stage? It helps to understand in advance how staging works under the TNM system.

A second opinion isn’t a sign of distrust in your doctor; it’s a way to make sure the decision rests on an accurate diagnosis and complete information. The better prepared your documents are, the more useful it will be.

Sources

1. Seeking a Second Opinion — American Cancer Society, patient guidance page
2. Second-opinion pathologic review is a patient safety mechanism that helps reduce error and decrease waste — Journal of Oncology Practice (MD Anderson Cancer Center), 2014
3. Breast pathology second review identifies clinically significant discrepancies in over 10% of patients — Journal of Surgical Oncology (MD Anderson Cancer Center), 2015
4. Is there evidence for a better health care for cancer patients after a second opinion? A systematic review — Journal of Cancer Research and Clinical Oncology (review on AHRQ PSNet), 2016
5. Статья 36.2 Федерального закона № 323-ФЗ «Об основах охраны здоровья граждан в Российской Федерации» (Article 36.2 of Federal Law No. 323-FZ “On the Fundamentals of Protecting the Health of Citizens in the Russian Federation”) — ConsultantPlus, as amended by Federal Law No. 242-FZ of 29 July 2017